Z. Li
,
Y.L. Yand
,
J.K Xi
,
J.X. Qu and H. S. Shao (Department of Materials Engineering
,
Luoyang institute of Technology
,
Luoyang 471039
,
China)(Beijing Graduate School
,
China University of Mining and Technology
,
Beijing 100083
,
China)
金属学报(英文版)
Annealing treatment has a strong effect on mechanical Properties of cold worked tungsten-nickel-iron heavy alloys. A 93W-4.5Ni-2.5Fe alloy swaged 15% was annealed from 500 to 1350℃ to investigate the changes in microstructure and their effects on mechanical properties. Recrystallization of W particles takes place during annealing treatments above 800℃ and the microhardnesses reduces rapidly. High density of dislocations in the, matrix phase after annealing treatment at 1350℃ suggests that recrystallization of the matrix phase has not taken place. A small decrease in microhardness of the matrix phase is caused by recovery during the annealing treatments.The changes in mechanical properties of swaged and annealed 93W-4.5 Ni-2.SFe alloy are mainly due to the changes in microstructure of W particles because of their recrystallization.
关键词:
: 93 W-4.5 Ni-2. 5 Fe alloy
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null
,
null
LIANG Yong LI Ruiguo Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
ChinaInstitute of Corrosion and Protection of Metals
,
Aademia Sinica
,
Shenyang
,
110015
,
China
材料科学技术(英文)
Recent advances in laser coating technology including laser cladding,laser surface alloying and laser vapour deposition in China are reviewed in this paper.
关键词:
laser
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null
,
null
,
null
,
null
QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
China
金属学报(英文版)
The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.
关键词:
stress corrosion cracking
,
null
,
null
,
null
Wear
Erosion-corrosion wear is a common failure type for many mining machine parts. This paper introduces the erosion-corrosion wear resistant, nickel based alloy coating, which is manufactured onto AISI 1045 steel by laser cladding technology. X-ray diffraction, scanning electron microscopy (SEM) and microhardness testing were used to investigate the microstructure and hardness of the coating. After that, erosion-corrosion wear experiments were carried out on an MSH type erosion-corrosion wear tester to study the erosion-corrosion wear characteristics of the laser clad coating. 420 stainless steel was also tested under the same conditions as a contrast specimen. The slurry was made up of water and quartz, while sulphuric acid was added to create corrosive condition. Experiments were arranged to test the relation between erosion-corrosion wear rate, the acid concentration and slurry erosion speed. Finally this gaper introduces the application of laser cladding technology to balance plates of slurry pumps used in underground mining. (C) 1997 Elsevier Science S.A.
关键词:
laser cladding;coating;erosion-corrosion wear;synergism